Sector scan control for antenna systems



April 4, 1950 M. D. MQFARLANE 2,502,975

SECTOR SCAN CONTROL FOR ANTENNA SYSTEMS Filed Sept. 25, 1944 l4 RO TATES WITH ANTENNA ARMAT ADJUSTABLE IMPULSE RELAY MAYNARD D.MCFARLANE Patented Apr. 4, 1950 UNITED STATES PATENT OFFICE SECTOR SCAN CONTROL FOR ANTENNA SYSTEMS tary of the Navy Application September 25, 1944, Serial No. 555,703

10 Claims. (01. 31s 2s2) This invention relates to a means for causing a rotatable member to oscillate back and forth about a given point and more particularly to a means for causing a rotatable antenna such as that used in radio echo detection systems to scan a given and adjustable sector about a predetermined bearing point.

It is an object of this invention to provide a means for causing an antenna to scan about a given point with means for adjusting the angle of scan and the bearing point about which the scan occurs.

Other objects and features of the present invention will become apparent upon a careful consideration of the following detailed description when taken together with the accompanying drawings, the single figure of which represents a preferred embodiment of the invention.

The single figure of the drawings is an elevational view of an antenna scan control mechanism constructed in accordance with the principles of the invention, certain brace and support members for which are omitted here for purposes of simplifying the illustration.

In reference to the figure there is shown an antenna ID or a spinner as it is sometimes known as, which is capable of scanning through 360 continuously. The antenna I9 is driven byv a drive motor H which is adapted to cyclically rotate the antenna back and forth under control of a reversing switch l2 and an impulse relay l3 or in either direction continuously whenever switch 26 is opened. More specifically relay l3 and reversing switch 52 is of a type now known to the art which is arranged in a first position of contact, in which it is sustained until the re lay receives a pulse of energization at which. time the switch l2 assumes a second position of contact where it is again sustained until the next succeeding pulse of energy whereupon the switch is returned to its original position of contact. Arranged with the antenna I and adapted to rotate therewith on an axis in space quadrature thereto is a crank like extension 14 upon which is mounted a switch 15, which is adapted to control the operation of relay I3 and switch I 2 whenever switch 26 is closed. Switch I5 is also of a type readily available in practice, adapted to be open circuited upon the application of pressure to a cam member 23 or other suitable means capable of controlling the contacts thereof. Leading from the relay I 3 are a pair of wires I5 and I! which connect to the switch I 5 through a pair of corresponding collector rings [8 and I9 which are carried by the member l4 at point 20, To control the operation of switch (5 and hence reversing switch l2 a cam member 2| is provided, suitably arranged in alignment with the axis of rotation of crank; like extension l4 and attached switch l5- lilcewise rotate about the cam member 2| so that as the cam follower 23 disengages the cam surface 22, from one side thereof, the relay I3 is. energized by means of battery 25 so as to operate the reversing switch 12 thereby changing the phase of the driving current to the armature of motor II and hence reversing the direction of rotation of the antenna. Whereupon the cam fo1- lower 23 will subsequently disengage the cam surface 22 from the opposite side thereof thus again energizing the relay l3 and switch l2 to restore the original phase of the driving current to the armature of motor II and hence the original direction of rotation to antenna ID. It is thus seen that the angle of antenna scan depends upon the perimeter of the cam surface 22, which may be adjusted by moving the cam member 2! in a longitudinal direction, while the bearing point about which the scan occurs may be controlled by adjusting the angular disposition of the cam surface 22.

Although I have shown and described only certain and specific embodiments of the present in.-

vention I am fully aware of the many modifica tions possible thereof therefore this invention is not to be limited except insofar as is necessitated by the prior art and the spirit of the appended claims.

What is claimed is: 1. A means for causing a rotatable member to oscillate back andforthabout a given point, comprising a driving motor, a relay operated reversing switch disposed in the armature circuit of said motor and adapted to control the direction of rotation of said motor, a cam member upon which is disposed a tapered cam surface, a second rotatable member arranged to rotate with the armature of said motor and upon which is mounted a second switch adapted to engage said cam member in such a manner as to operate said relay controlled reversing switch whenever said second switch disengages said cam surface.

2. In apparatus for causing a member to oscillate, means for controlling the angle of said oscillation and the midposition of said oscillation comprising a driving motor coupled to said member, means adapted to reverse the direction of rotation of said motor, a cam member upon which is dis- .posed a tapered cam surface, said cam member being adapted to be moved laterally and in rotation, a second member arranged to rotate with said first-mentioned member, and a follower mounted on said second member and adapted to engage said cam and cam surface,- said follower being further adapted to control the operation of said motor reversing means.

3. Apparatus as in claim 2 said apparatus further comprising means for disabling said motor reversing means whereby said firstmentioned member is caused to rotate continuously in one direction.

4. In apparatus for causing a member to US$11." late, means for cnt1011ing the angle of said oscillation comprising a driving motor coupled to said member, means adapted to reverse the direction of rotation of said motor, a cam member upon-which is disposed anelongated, tapered cam surface, said cam. member bein adapted. to be moved laterally and. in. rotation, a second member arranged to rotate withv said first-mentioned. member, and a follower mounted. on. said second member and. adapted to engage said. cam surface, said follower being further adapted to control the operation of said motor reversing means.

5. In apparatus; for causing a member to oscillate, means for controlling the angle of. said oscillation and the midposition of said oscillation. comprising a driving motor coupled to. said member, a relay operated switch adapted to reverse the direction of. rotation. of said motor, a cam member upon which is disposed a tapered cam surface, said cam member being adapted to be moved laterally and in rotation, a second member arranged to" rotate with said. first-mentioned member and a switch mounted on said second member and adapted to be operated by said cam surface, said switch being further adapted to control the operation of said relay operated switch.

6. Apparatus as in claim 5 said apparatus further comprising means for rendering said relay opera-ted switch inoperative whereby said firstmentioned member is caused to rotate continuously in one direction.

7. In apparatus for causing a member to oscillate, means' for controlling the angle of said oscillation and the midposition of said oscillation comprising a driving motor coupled to said member, a relay operated switch adapted to reverse the direction of rotation of said motor, a cam member upon which is disposed an elongated, tapered cam surface, said cam member being adapted to be moved laterally and in rotation, a second member arranged to rotate with said first-mentioned member and a switch mounted onsaid second member and adapted to be operated by said cam surface, said switch being connected to control the operation of said relay.

8. In apparatus for causing a member to oscillate, means for controlling the angle of said oscillation comprising a driving motor coupled to said member, means adapted to reverse the direction of rotation of said motor, an elongated, cylindrical cam member upon which is disposed atapered cylindrical canr surface, said cam being adapted to be moved along the direction of the axis thereof and in rotation about said axis, a second member arranged to rotate with said first-mentioned member, and a follower mounted on said second member and adapted to engage said cam and said cam surface, said follower being further adapted to control the operation of said motor reversing means.

" greater angle at a second position onthe axis of said cam, said cam being adapted to be moved. along the direction of said axis and. in rotation about said axis, a second member arranged to rotate with said first-mentioned member, and. a follower mounted on said second member and adapted to engage said cam and said cam surface, said follower being further adapted to control' the operation of said motor reversing means.

10. In apparatus for causing a member to oscillate, means for controlling the angle of said oscillation and. the midposition of said oscillation comprising, a driving motor coupled to said member, a relay operated switch adapted to reverse the direction of rotation of said motor, an elongated cylindrical cam member upon which is mounted a cylindrical cam surface, said cam surface being included within a first angle at one point on the axis. of said. cam and within a second and greater. angle at a second point on the axis of said. cam, said cam being adapted to be moved in the direction of said. axis and in rotation about said axis, a second member ar-;

ranged. to rotate with said first-mentioned membet, and a switch mounted on said second member and" adapted to be operated by said cam surface, said switch being further adaptedv to control' the operation of said relay operated switch.

MAYNARD D. MCFARLANE.

REFERENCES" CITED The following. references are of; record in the file of this patent:

UNITED STATES PATENTS- Name Date Smith May 21, 1932' Number 

